DESCRIPTION: Total mortality in the U.S. elderly population has changed significantly due to declines in circulatory disease mortality and, until recently, stable or slowly-increasing mortality from cancer. Additionally, recent research suggests that, even at advanced ages, morbidity and disability can be modified significantly before death-and influence the set of diseases most responsible for death-through lifestyle changes, some related cohort experiences, changes in medical technology, and changes in the access to health care. The investigators will examine temporal and cohort changes in the causes of mortality using several types of data-each with characteristic strengths. One type, multiple cause of death data, is now available for a long-enough period of time that cohort differences in the multiple conditions reported at death can be examined. Other data, from longitudinal population studies, provide information on the temporal relation of morbidity and disability changes for lengthy periods prior to death. This adds a crucial intra-individual temporal dimension to analyses of human failure processes at late ages. To analyze these data the investigators will use statistical estimation strategies designed for analyzing combinations of longitudinal demographic and health survey data sets-each with different statistical and measurement properties. With these data and methods the project will examine hypotheses about the recent (1991-1995) emergence of the first persistent U.S. declines in overall cancer mortality, i.e. what ages does it affect most, which types of cancer changed most, were changes due to prevention or improvements in treatment, how was the estimate of the cancer decline affected by trends in circulatory disease death? The investigators will also examine hypotheses about changes in the age dominance of specific conditions, e.g. what types of circulatory disease, and co-conditions, emerge at, say, ages 65 to 75 vs. ages 85+? This will produce insights into changes in human mortality processes at advanced ages, where growing numbers of deaths will occur in the future as the U.S. population ages and the numbers of nonagenarians and centenarians increase. This is important in forecasting life expectancy and the growth of the extremely elderly U.S. population.